Yukio Watanabe

Hydroxynitrile lyase (HNL) from the cyanogenic millipede Oxidus gracillis (OgraHNL) is a crucial enzyme in the cyanogenesis pathway. Here, the crystal structures of OgraHNL complexed with sulfate, benzaldehyde (BA), (R)‐mandelonitrile ((R)‐Man), (R)‐2‐chloromandelonitrile ((R)‐2‐Cl−Man), and acetone cyanohydrin (ACN) were solved at 1.6, 1.7, 2.3, 2.1, and 2.0 Å resolutions, respectively. The structure of OgraHNL revealed that it belonged to the lipocalin superfamily. Based on this structure, positive variants were designed to further improve the catalytic activity and enantioselectivity of the enzyme for asymmetric hydrocyanation and Henry reactions.

Ammonia is an important chemical that is widely used in fertilizer applications as well as in the steel, chemical, textile, and pharmaceutical industries, which has attracted attention as a potential fuel. Thus, approaches to achieve sustainable ammonia production have attracted considerable attention. In particular, biological approaches are important for achieving a sustainable society because they can produce ammonia under mild conditions with minimal environmental impact compared with chemical methods. For example, nitrogen fixation by nitrogenase in heterogeneous hosts and ammonia production from food waste using microorganisms have been developed. In addition, crop production using nitrogen-fixing bacteria has been considered as a potential approach to achieving a sustainable ammonia economy. This review describes previous research on biological ammonia production and provides insights into achieving a sustainable society.

A sustainable society was proposed more than 50 years ago. However, it is yet to be realised. For example, the production of ammonia, an important chemical widely used in the agriculture, steel, chemical, textile, and pharmaceutical industries, still depends on fossil fuels. Recently, biological approaches to achieve sustainable ammonia production have been gaining attention. Moreover, unlike chemical methods, biological approaches have a lesser environmental impact because ammonia can be produced under mild conditions of normal temperature and pressure. Therefore, in previous studies, nitrogen fixation by nitrogenase, including enzymatic ammonia production using food waste, has been attempted. Additionally, the production of crops using nitrogen-fixing bacteria has been implemented in the industry as one of the most promising approaches to achieving a sustainable ammonia economy. Thus, in this review, we described previous studies on biological ammonia production and showed the prospects for realising a sustainable society.

Objectives: To overcome the lack of the autografts in revision ear surgery, the usefulness of human amniotic membrane (AM) patches as a dressing substitute for fascia grafts of the temporal muscle (temporalis fascia graft) was investigated in canal wall down tympanoplasty. Study Design: Retrospective chart review. Methods: In 11 ears of 11 patients, the AM was attached over the bony surface of the mastoid cavity (AM group). In 11 ears of nine patients, the temporalis fascia graft was attached over the bony surface of the mastoid cavity (fascia group). The times for graft epithelization were compared in both groups. Results: In both groups, complete epithelization of the mastoid cavity took place in all patients. The time of epithelization in the AM group was 32 days, whereas in the fascia group it was 45 days. Complete epithelization of the AM graft was significantly faster than the fascia graft (P < .05). Conclusions: Hyperdry AM might be a new useful dressing substitute for temporalis fascia graft due to the reduction in the epithlializing time offered by the AM in revision ear surgery.

The purpose of this study was to investigate how gravity affects the vestibular evoked myogenic potential (VEMP). Eight healthy subjects (seven men, one woman; age range 19–45 years) participated in experiments in which three different gravity levels [microgravity (MG), normal gravity (NG), and hypergravity (HG)] were imposed during a parabolic flight procedure. The VEMP was evoked in response to an intense mono-aural click while the subjects kept the sternocleidomastoid (SCM) muscle contracted bilaterally. Background electromyographic activity of the SCM during the test was corrected. The p13–n23 amplitude was significantly greater under MG than under NG or HG. There was no difference in p13 latency between the three gravity levels. Possible mechanisms related to this phenomenon are discussed.

• The cleavage of nuclear DNA into oligonucleosomal fragments that is the hallmark of apoptosis in animal cells occurs during the culture of Brass...